Apparatus and methods of displaying navigation instructions

ABSTRACT

A device is disclosed for generating navigation instructions for display on a display device of a portable navigation device, comprising: means for accessing a repository storing digital map data pertaining to a navigable network along which the navigation device can travel, the digital map data including data pertaining to available lanes of the navigable network; means for generating, for display on the display device, a three-dimensional perspective view of a model representative of the map data as though from a camera positioned at an elevation and pitch angle behind a current position of the portable navigation device, that is updated to follow the device as it travels along a planned route, wherein the three-dimensional perspective view shows the available lanes of the navigable network, and wherein the planned route to be followed is shown in the view as a line, the line showing the route to be followed as passing along a determined current lane in which the device is travelling; and means for adapting the generated view, in response to detecting that the determined current lane in which the device is travelling differs from a lane or lanes associated with a manoeuvre to be made at an upcoming decision point in order to follow the planned route, such that the line showing the route to be followed indicates an instruction to the user to change lanes. Methods of operation of the device, and related computer software, are also disclosed.

The present application is the National Stage of InternationalApplication No. PCT/EP2014/071756, filed Oct. 10, 2014 and designatingthe United States, which claims benefit to United Kingdom PatentApplication GB 1318049.2 filed on Oct. 11, 2013, GB 1320360.9 filed onNov. 18, 2013, and GB 1400161.4 filed on Jan. 6, 2014. The entirecontent of these applications is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to methods and systems for generating anddisplaying navigation instructions to user, preferably in respect ofcalculated route to a destination. Illustrative embodiments of theinvention relate to portable navigation devices (so-called PNDs), inparticular PNDs that include means for determining their currentposition.

BACKGROUND TO THE INVENTION

Portable navigation devices (PNDs) that include global navigationsatellite systems (GNSS), e.g. global positioning system (GPS), signalreception and processing functionality are well known, and are widelyemployed as in-car or other vehicle navigation systems. It will beappreciated, that portable navigation devices may use other means todetermine their location, such as using the mobile telecommunications,surface beacons or the like.

In general terms, a modern PND comprises a processor, memory (at leastone of volatile and non-volatile, and commonly both), and map datastored within said memory. The processor and memory cooperate to providean execution environment in which a software operating system may beestablished, and additionally it is commonplace for one or moreadditional software programs to be provided to enable the functionalityof the PND to be controlled, and to provide various other functions.

Typically these devices further comprise one or more input interfacesthat allow a user to interact with and control the device, and one ormore output interfaces by means of which information may be relayed tothe user. Illustrative examples of output interfaces include a visualdisplay and a speaker for audible output. Illustrative examples of inputinterfaces include one or more physical buttons to control on/offoperation or other features of the device (which buttons need notnecessarily be on the device itself but could be on a steering wheel ifthe device is built into a vehicle), and a microphone for detecting userspeech. In a particularly preferred arrangement the output interfacedisplay may be configured as a touch sensitive display (by means of atouch sensitive overlay or otherwise) to additionally provide an inputinterface by means of which a user can operate the device by touch.

Devices of this type will also often include one or more physicalconnector interfaces by means of which power, and optionally datasignals, can be transmitted to and received from the device, andoptionally one or more wireless transmitters/receivers to allowcommunication over cellular telecommunications and other signal and datanetworks, for example Wi-Fi, Wi-Max GSM and the like.

PND devices of this type also include a GPS antenna by means of whichsatellite-broadcast signals, including location data, can be receivedand subsequently processed to determine a current location of thedevice.

The PND device may also include electronic gyroscopes and accelerometerswhich produce signals that can be processed to determine the currentangular and linear acceleration, and in turn, and in conjunction withlocation information derived from the GPS signal, velocity and relativedisplacement of the device and thus the vehicle in which it is mounted.Typically such features are most commonly provided in in-vehiclenavigation systems, but may also be provided in PND devices if it isexpedient to do so.

The utility of such PNDs is manifested primarily in their ability todetermine a route between a first location (typically a start or currentlocation) and a second location (typically a destination). Theselocations can be input by a user of the device, by any of a wide varietyof different methods, for example by postcode, street name and housenumber, previously stored “well known” destinations (such as famouslocations, municipal locations (such as sports grounds or swimming bathsor other points of interest), and favourite or recently visiteddestinations.

Typically, the PND is enabled by software for computing a “best” or“optimum” route between the start and destination address locations fromthe map data. A “best” or “optimum” route is determined on the basis ofpredetermined criteria and need not necessarily be the fastest orshortest route. The selection of the route along which to guide thedriver can be very sophisticated, and the selected route may take intoaccount historical, existing and/or predicted traffic and roadinformation.

In addition, the device may continually monitor road and trafficconditions, and offer to or choose to change the route over which theremainder of the journey is to be made due to changed conditions. Realtime traffic monitoring systems, based on various technologies (e.g.mobile phone data exchanges, fixed cameras, GPS fleet tracking) arebeing used to identify traffic delays and to feed the information intonotification systems.

PNDs of this type may typically be mounted on the dashboard orwindscreen of a vehicle, but may also be formed as part of an on-boardcomputer of the vehicle radio or indeed as part of the control system ofthe vehicle itself. The navigation device may also be part of ahand-held system, such as a PDA (Portable Digital Assistant) a mediaplayer, a mobile phone or the like, and in these cases, the normalfunctionality of the hand-held system is extended by means of theinstallation of software on the device to perform both route calculationand navigation along a calculated route.

Route planning and navigation functionality may also be provided by adesktop or mobile computing resource running appropriate software. Forexample, an on-line route planning and navigation facility is providedat routes.tomtom.com, which facility allows a user to enter a startpoint and a destination, whereupon the server to which the user's PC isconnected calculates a route (aspects of which may be user specified),generates a map, and generates a set of exhaustive navigationinstructions for guiding the user from the selected start point to theselected destination. The facility also provides for pseudothree-dimensional rendering of a calculated route, and route previewfunctionality which simulates a user travelling along the route andthereby provides the user with a preview of the calculated route.

In the context of a PND, once a route has been calculated, the userinteracts with the navigation device to select the desired calculatedroute, optionally from a list of proposed routes. Optionally, the usermay intervene in, or guide, the route selection process, for example byspecifying that certain routes, roads, locations or criteria are to beavoided or are mandatory for a particular journey. The route calculationaspect of the PND forms one primary function, and navigation along sucha route is another primary function.

A further important function provided by the device is automatic routere-calculation in the event that: a user deviates from the previouslycalculated route during navigation (either by accident orintentionally); real-time traffic conditions dictate that an alternativeroute would be more expedient and the device is suitably enabled torecognize such conditions automatically, or if a user actively causesthe device to perform route re-calculation for any reason.

Although the route calculation and navigation functions are fundamentalto the overall utility of PNDs, it is possible to use the device purelyfor information display, or “free-driving”, in which only mapinformation relevant to the current device location is displayed, and inwhich no route has been calculated and no navigation is currently beingperformed by the device. Such a mode of operation is often applicablewhen the user already knows the route along which it is desired totravel and does not require navigation assistance.

Devices of the type described above provide a reliable means forenabling users to navigate from one position to another.

During navigation along a calculated route, it is usual for such PNDs toprovide visual and/or audible instructions to guide the user along achosen route to the end of that route, i.e. the desired destination. Itis also usual for PNDs to display map information on-screen during thenavigation, such information regularly being updated on-screen so thatthe map information displayed is representative of the current locationof the device, and thus of the user or user's vehicle if the device isbeing used for in-vehicle navigation.

An icon displayed on-screen typically denotes the current devicelocation, and is centred with the map information of the current roadand surrounding roads in the vicinity of the current device location andother map features also being displayed. Additionally, navigationinformation may be displayed, optionally in a status bar above, below orto one side of the displayed map information, examples of navigationinformation include a distance to the next deviation from the currentroad required to be taken by the user, the nature of that deviationpossibly being represented by a further icon suggestive of theparticular type of deviation, for example a left or right turn. Thenavigation function also determines the content, duration and timing ofaudible instructions by means of which the user can be guided along theroute. As can be appreciated a simple instruction such as “turn left in100 m” requires significant processing and analysis. As previouslymentioned, user interaction with the device may be by a touch screen, oradditionally or alternately by steering column mounted remote control,by voice activation or by any other suitable method.

As mentioned above, there are a number of typical ways of providingnavigation instructions to a user to allow them to follow apredetermined route; such navigation instructions commonly beingreferred to as turn-by-turn instructions. Most rely on displaying arepresentation of the world, and typically the road network, around thecurrent position of the device and/or user, together with graphicalicons indicating the current position of the device and/user and theroute to be followed. The representation of the world will typically bea computer generated image from a particular point of view.

For example, one common representation is a two-dimensional (2D) view inwhich an image is generated as though from a camera (see FIG. 4C)positioned at an elevated position, in the z-direction, and with a pitchangle of 0° so as to show a bird's eye view of the area around thecurrent position of the device. An example of such a view is shown inFIG. 4A and in which the current position of the device is shown by icon401 and the predetermined route being followed is shown by the line 403.In this view, the camera may move in the x-y plane (i.e. the planeperpendicular to the z-axis and thus parallel to the surface on whichthe device is moving) so as to track the movements of the device alongthe route.

Another common representation is a three-dimensional (3D) view in whichan image is generated as though from a camera positioned at an elevatedposition, but which has a pitch angle of 30° for example (a 90° pitchangle being such that the camera is pointed parallel to the plane of thesurface) so as to show a perspective view of the area around the currentposition of the device. An example of such a view is shown in FIG. 4B,and wherein it will be appreciated the camera is located at apredetermined position behind the current position of the device, i.e.in the x-y plane, based on the direction of travel of the device, sothat an icon 405 representative of the current position of the devicecan be shown in the view. In this view the camera will typically trackthe movements of the device along the predetermined route 407; theviewing angle of the camera thus being centred along the direction oftravel of the device (or along the path of the predetermined route).

For some complex junctions, it is also known to show a combination ofthe 3D guidance view together with a schematic view of the approachingjunction to the user showing the manoeuvre to be made in more detail. Anexample of such a view is shown in FIG. 5 in which the guidance view 500is shown on the left side of the screen and the junction view 501 isshown on the right side of the screen. More specifically, the guidanceview 500 displays the route to be followed by the line 502, the currentposition of the device by the icon 503, and the manoeuvre to be made atthe next junction by the arrow 404. Meanwhile, in the junction view 501,the arrows 408 indicate which lanes of the road the user needs to be into complete the desired manoeuvre. Despite these improvements to thestandard guidance modes, e.g. as shown in FIGS. 4A and 4B, however, theApplicant has recognised that since two screens 500 and 501 are neededto provide the user with sufficient information to perform a manoeuvre,and the user is required to take different information from each screen,then this can lead to confusion.

Another method of providing navigation (or guidance) instructions is tosuperpose the instructions over images from a camera showing the area infront of the device in order to “augment reality”. Additional detailsabout such devices can be found, for example, in WO 2006/132522 A1published 14 Dec. 2006; the entire content of which is incorporatedherein by reference. Similarly, and rather than superposing theinstructions over a camera image and displaying the resultantcombination on a display screen, it is also known to project theinstructions, e.g. onto surface, as part of a heads-up display (HUD)such that the user can see the instructions in their field of view Aswill be appreciated, however, and particularly in the case of complexjunctions and intersections, displaying instructions in this manner donot always provide the user with sufficient insight as to thecomposition of an approaching junction or the manoeuvres that need to bemade at the junction.

The Applicant has therefore realised that there remains a need forimproved methods of displaying navigation instructions to a user.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention there is provided amethod of generating navigation instructions for display on a displaydevice of a portable navigation device, the method comprising:

accessing a repository storing digital map data pertaining to anavigable network along which the navigation device can travel;

generating, for display on the display device, a three-dimensionalperspective view of a model representative of the map data as thoughfrom a camera positioned at an elevation and pitch angle behind acurrent position of the portable navigation device, that is updated tofollow the device as it travels along a planned route through thenavigable network; and generating, in response to detecting that thecurrent position of the navigation device is closer than a predetermineddistance to a decision point in the planned route, a fast forwardpreview of the upcoming decision point by advancing the position of thecamera for the three-dimensional perspective view along the plannedroute at a speed faster than the rate of travel of the current positionof the device.

The present invention extends to a device, preferably a navigationdevice, for carrying out a method in accordance with any of the aspectsor embodiments of the invention herein described.

Thus, in accordance with a second aspect of the invention there isprovided a device for generating navigation instructions for display ona display device of a portable navigation device, the device comprising:

means for accessing a repository storing digital map data pertaining toa navigable network along which the navigation device can travel;

means for generating, for display on the display device, athree-dimensional perspective view of a model representative of the mapdata as though from a camera positioned at an elevation and pitch anglebehind a current position of the portable navigation device, that isupdated to follow the device as it travels along a planned route throughthe navigable network; and

means for generating, in response to detecting that the current positionof the navigation device is closer than a predetermined distance to adecision point in the planned route, a fast forward preview of theupcoming decision point by advancing the position of the camera for thethree-dimensional perspective view along the planned route at a speedfaster than the rate of travel of the current position of the device.

As will be appreciated by those skilled in the art, this further aspectof the present invention can and preferably does include any one or moreor all of the preferred and optional features of the invention describedherein in respect of any of the other aspects of the invention, asappropriate. If not explicitly stated, the device of the presentinvention herein may comprise means for carrying out any step describedin relation to the method of the invention in any of its aspects orembodiments, and vice versa.

The present invention is a computer implemented invention, and any ofthe steps described in relation to any of the aspects or embodiments ofthe invention may be carried out under the control of a set of one ormore processors. The means for carrying out any of the steps describedin relation to the system may be a set of one or more processors.

In general, the device of the present invention in any of itsembodiments may be at least one processing device. The or a processingdevice may be a navigation device, whether a portable navigation device(PND) or an integrated device, or may be a server.

In embodiments where the method is implemented on a navigation device,the device comprises position detection means for determining theposition of the device, e.g. a global navigation satellite system(GNSS), e.g. GPS or GLONASS, receiver. As will be appreciated the devicemay use other means for determining its current location as desired,e.g. terrestrial beacons, the mobile telecommunications network, etc.

Accordingly, in an embodiment, there is provided a portable navigationdevice, comprising:

one or more processors;

position detection means for determining the position of the navigationdevice;

a display device;

repository storing digital map data pertaining to a navigable networkalong which the navigation device can travel; and

memory comprising instructions which when executed by one or more of theprocessors causes the navigation device to:

-   -   generate, for display on the display device, a three-dimensional        perspective view of a model representative of the map data as        though from a camera positioned at an elevation and pitch angle        behind a current detected position of the navigation device,        that is updated to follow the device as it travels along a        planned route through the navigable network; and    -   generate, in response to detecting that the current position of        the navigation device is closer than a predetermined distance to        a decision point in the planned route, a fast forward preview of        the upcoming decision point by advancing the position of the        camera for the three dimension perspective view along the        planned route at a speed faster than the rate of travel of        travel of the current position of the device.

In embodiments where the method is implemented on a server, the serverpreferably periodically receives the current position of a navigationdevice, and transmits the generated navigation instructions for displayon a display device of the navigation device.

In embodiments, the pitch angle of the camera and/or the elevation ofthe camera are changed during the fast forward preview. The pitch anglemay be increased during the fast forward preview from between 20° to 40°to between 50° to 70°. The elevation may be decreased during the fastforward preview. Thus, in embodiments, the camera is altered so as toprovide an apparent zoomed in view during the fast forward preview. Inembodiments, the fast forward preview is such that the current positionof the device is no longer visible in the preview. Preferably, the pitchangle and elevation of the camera are changed back once the cameraresumes tracking the current position of the device.

Therefore, it will be appreciated that, during the fast forward preview,the position of the camera is preferably advanced to the decision pointfaster than the device whereupon the camera stops to provide a previewof the decision point. In such embodiments, when the current position ofthe device catches up with the camera at the decision point, the cameraresumes tracking the current position of the device.

In embodiments, instructions further cause the fast forward preview ofthe decision point to be abandoned such that the camera moves to revertto tracking the current position of the device manually, on receipt ofuser input, or automatically, in response to slow progress of theposition of the device or a deviation from a planned route. Inembodiments, the device is further operable to cause the previouslyabandoned fast forward preview of the decision point to be resumed inresponse to user input and/or resumed progress in the rate of travel ofthe device.

In embodiments, the navigable network is a road network and thepredetermined distance is dependent on a functional road class of theroad the device is currently travelling along as stored in the digitalmap data.

In embodiments, the decision point in the digital map is a junction oran intersection or a location within the digital map where a user of thedevice is able to opt to navigate along one of a number of availableroutes in the navigable network, including the planned route.

In embodiments, the method further comprises generating, for display onthe display device, a line to be followed indicating the planned route,wherein the three-dimensional perspective view shows the available lanesof the navigable network and the line shows the route to be followed aspassing along a determined current lane in which the device istravelling. In response to detecting that the determined current lane inwhich the device is travelling differs from a lane or lanes associatedwith a manoeuvre to be made at an upcoming decision point, e.g. anapproaching junction, in order to follow the planned route, thegenerated view is adapted such that the line showing the route to befollowed indicates an instruction to the user to change lanes.

It is considered that the generation of navigation instructionsindicating that a user needs to change lanes is new and inventive in itsown right.

Thus, according to another aspect of the invention there is provided amethod of generating navigation instructions for display on a displaydevice of a portable navigation device, the method comprising:

accessing a repository storing digital map data pertaining to anavigable network along which the navigation device can travel, thedigital map data including data pertaining to available lanes of thenavigable network;

generating, for display on the display device, a three-dimensionalperspective view of a model representative of the map data as thoughfrom a camera positioned at an elevation and pitch angle behind acurrent position of the portable navigation device, that is updated tofollow the device as it travels along a planned route, wherein thethree-dimensional perspective view shows the available lanes of thenavigable network, and wherein the planned route to be followed is shownin the view as a line, the line showing the route to be followed aspassing along a determined current lane in which the device istravelling; and

adapting the generated view, in response to detecting that thedetermined current lane in which the device is travelling differs from alane or lanes associated with a manoeuvre to be made at an upcomingdecision point in order to follow the planned route, such that the lineshowing the route to be followed indicates an instruction to the user tochange lanes.

The present invention extends to a device, preferably a navigationdevice, for carrying out a method in accordance with any of the aspectsor embodiments of the invention herein described.

Thus, in accordance with a further aspect of the invention there isprovided a device for generating navigation instructions for display ona display device of a portable navigation device, the device comprising:

means for accessing a repository storing digital map data pertaining toa navigable network along which the navigation device can travel, thedigital map data including data pertaining to available lanes of thenavigable network;

means for generating, for display on the display device, athree-dimensional perspective view of a model representative of the mapdata as though from a camera positioned at an elevation and pitch anglebehind a current position of the portable navigation device, that isupdated to follow the device as it travels along a planned route,wherein the three-dimensional perspective view shows the available lanesof the navigable network, and wherein the planned route to be followedis shown in the view as a line, the line showing the route to befollowed as passing along a determined current lane in which the deviceis travelling; and

means for adapting the generated view, in response to detecting that thedetermined current lane in which the device is travelling differs from alane or lanes associated with a manoeuvre to be made at an upcomingdecision point in order to follow the planned route, such that the lineshowing the route to be followed indicates an instruction to the user tochange lanes.

As will be appreciated by those skilled in the art, this further aspectof the present invention can and preferably does include any one or moreor all of the preferred and optional features of the invention describedherein in respect of any of the other aspects of the invention, asappropriate. If not explicitly stated, the device of the presentinvention herein may comprise means for carrying out any step describedin relation to the method of the invention in any of its aspects orembodiments, and vice versa.

The present invention, in accordance with these further aspects, is acomputer implemented invention, and any of the steps described inrelation to any of the aspects or embodiments of the invention may becarried out under the control of a set of one or more processors. Themeans for carrying out any of the steps described in relation to thesystem may be a set of one or more processors.

In general, the device of the present invention in any of itsembodiments may be at least one processing device. The or a processingdevice may be a navigation device, whether a portable navigation device(PND) or an integrated device, or may be a server.

Accordingly, in an embodiment, there is provided a portable navigationdevice, comprising:

one or more processors;

position detection means for determining the position of the navigationdevice;

a display device;

repository storing digital map data pertaining to a navigable networkalong which the navigation device can travel, the digital map dataincluding data pertaining to the available lanes of the navigablenetwork; and

memory comprising instructions which when executed by one or more of theprocessors causes the navigation device to:

-   -   generate, for display on the display device, a three-dimensional        perspective view of a model representative of the map data as        though from a camera positioned at an elevation and pitch angle        behind a current position of the portable navigation device,        that is updated to follow the device as it travels along a        planned route, wherein the three-dimensional perspective view        shows the available lanes of the navigable network, and wherein        the planned route to be followed is shown in the view as a line,        the line showing the route to be followed as passing along a        determined current lane in which the device is travelling; and    -   adapt the generated view, in response to detecting that the        determined current lane in which the device is travelling        differs from a lane or lanes associated with a manoeuvre to be        made at an upcoming decision point in order to follow the        planned route, such that the line showing the route to be        followed indicates an instruction to the user to change lanes.

In embodiments, the instruction to change lanes is associated with themanoeuvre to be made at the upcoming decision point, e.g. approachingjunction, in order to follow the planned route.

In embodiments, the instruction is provided by the line showing theroute to be followed being shaped to indicate to the user that thecurrent lane should be changed before the upcoming decision point, e.g.approaching junction.

The instruction may be shown at a predetermined distance or time fromthe junction. Alternatively, the instruction may be positioned at thefirst opportunity to change lanes for the upcoming decision point, e.g.approaching junction.

In embodiments, and in response to a determination that a current laneof the device is changed in accordance with the instruction, thegenerated view is adapted such that the line showing the route to befollowed no longer shows the instruction to the user to change lanes.

In embodiments, the line showing the route to be followed continues toindicate the instruction to the user to change lanes as the movement ofthe device is followed, until a determination is made that the currentlane of the device is changed in accordance with the instruction. Thecontinual indication may be provided by the instruction movingconcurrently with the position of the device, until a determination ismade that the current lane of the device is changed in accordance withthe instruction. In embodiments, once the current position of the deviceis a predetermined distance before the instruction, the instructionmoves concurrently with the position of the device, thereby maintainingthe predetermined distance between the position of the device and theinstruction, until a determination is made that the current lane of thedevice is changed in accordance with the instruction.

In embodiments, the available lanes of the navigable network are shownin the three-dimensional perspective view by way of road markings,optionally virtual road markings generated based on data stored in themap database. Preferably, the road markings are only shown in therendered view on parts of the navigable network relevant to the plannedroute. Preferably, the road markings are only shown in the rendered viewon parts of the navigable network local to the detected position of thedevice.

In embodiments, the digital map data includes data pertaining to anumber of lanes available at least in a section of the navigablenetwork, optionally further comprising data pertaining to the laneindications for manoeuvres at junctions.

In embodiments, the line showing the route to be followed covers allpossible lanes that can be occupied to successfully complete themanoeuvre to be made at an approaching junction in order to follow theplanned route.

In embodiments, the current lane of the navigable network in which thedevice is travelling is determined from a data feed received from a lanedetermination means, which optionally can be separate from the portablenavigation device (albeit operatively connected thereto). The currentlane of the device may be determined based on data received from one ormore of a camera, lidar sensor, radar, GNSS receiver, and an inertialmeasurement unit.

Any of the methods in accordance with the present invention may beimplemented at least partially using software, e.g. computer programs.The present invention thus also extends to a computer program comprisingcomputer readable instructions executable to perform, or to cause adevice, e.g. portable navigation device and/or server, to perform amethod according to any of the aspects or embodiments of the invention.

The invention correspondingly extends to a computer software carriercomprising such software which, when used to operate a system orapparatus comprising data processing means causes, in conjunction withsaid data processing means, said apparatus or system to carry out thesteps of the methods of the present invention. Such a computer softwarecarrier could be a non-transitory physical storage medium such as a ROMchip, CD ROM or disk, or could be a signal such as an electronic signalover wires, an optical signal or a radio signal such as to a satelliteor the like. The present invention provides a machine readable mediumcontaining instructions which when read by a machine cause the machineto operate according to the method of any of the aspects or embodimentsof the invention.

Where not explicitly stated, it will be appreciated that the inventionin any of its aspects may include any or all of the features describedin respect of other aspects or embodiments of the invention to theextent they are not mutually exclusive. In particular, while variousembodiments of operations have been described which may be performed inthe method and by the apparatus, it will be appreciated that any one ormore or all of these operations may be performed in the method and bythe apparatus, in any combination, as desired, and as appropriate.

It will also be appreciated that whilst the provision of a fast forwardpreview of the upcoming decision point has been discussed in relation toa planned route through the navigable network, it is also envisionedthat such functionality may be provided in relation to any decisionpoints that may be encountered during traversal of the navigable networkregardless of whether a route has previously been planned or not. Forexample, if the user is “free-driving”, i.e. driving without havingfirst calculated a route to be followed, a fast forward preview may beprovided for each upcoming decision point (or only those meeting certainpredetermined criteria).

Advantages of these embodiments are set out hereafter, and furtherdetails and features of each of these embodiments are defined in theaccompanying dependent claims and elsewhere in the following detaileddescription.

BRIEF DESCRIPTION OF THE FIGURES

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying Figures, in which:

FIG. 1 is a schematic illustration of an exemplary part of a GlobalPositioning System (GPS) usable by a navigation device;

FIG. 2 is a schematic illustration of electronic components of anexemplary navigation device;

FIG. 3 is a schematic diagram of an arrangement of mounting and/ordocking an exemplary navigation device;

FIG. 4A shows an exemplary 2D guidance view as used in conventionalnavigation devices, and FIG. 4B shows an exemplary 3D guidance view asused in conventional navigation devices (generated using a camera withproperties shown in FIG. 4C);

FIG. 5 shows a combination of a 3D guidance view together with aschematic view of an approaching junction that can be used for complexjunctions in conventional navigation devices;

FIG. 6A shows en exemplary view of a junction that is displayed on adisplay device of a navigation device, and FIG. 6B shows the samejunction when viewed by the driver through the windscreen of theirvehicle;

FIG. 7 shows an example of various components used to create a 3Dguidance view in accordance with embodiments of the invention;

FIGS. 8A to 8J show a fast forward preview of an approaching junction inaccordance with embodiments of the invention;

FIG. 9 shows the changes in speed, elevation and pitch angle of thecamera when performing the fast forward preview of FIGS. 8A to 8J;

FIGS. 10A and 10B show embodiments of the guidance view in whichgraphical icons can be selected to initiate or cancel a fast forwardpreview;

FIG. 11 illustrates an embodiment of the guidance view in whichdistinctions are made between more and less relevant roads;

FIG. 12 illustrates an embodiment of the guidance view in which thetransparency of the displayed calculated route being followed is varied;

FIG. 13 illustrates an embodiment of the guidance view in which thedisplayed route encompasses any lane that the user is able to travel;

FIGS. 14A and 14B illustrate an embodiment of the guidance view in whichthe view is supplemented with additional information

FIGS. 15A and 15B, and FIGS. 16A to 16F, illustrate an exemplary mannerof providing lane guidance in accordance with embodiments of theinvention.

DETAILED DESCRIPTION OF THE FIGURES

It has been recognised that there is a desire to provide a navigationview which provides all the information required by a user in a focussedand straightforward manner, and which is more than just a repetition ofwhat can be seen by the driver simply by looking around them. This isachieved, for example, by generating a realistic view of the area, e.g.road, buildings, etc, around and ahead of the user, and providingadditional information to this view such as one or more of certain lanemarkings, an indication of the route to be followed, an indication ofthe lanes to be used, road signs, the phase of a traffic control signal.An example of such a view is shown by FIG. 6A in which a user isapproaching a complicated junction 600 with multiple roads intersecting.The path to be followed by the user is shown by the line 601, and thecurrent position of the user is shown by the icon 602. The number oflanes on at least the current road is shown through the use of lanedividers 604; with arrows 606 showing the possible manoeuvres that canbe made for each lane at the approaching junction 600. The view may alsoshow features such as pedestrian crossings 608 and “right of way”indicators on the current road to provide further information to theuser. By comparison the view of the same junction 600 as seen by thedriver through the windscreen of their vehicle is shown in FIG. 6B.

Embodiments of the present invention will now be described withparticular reference to a Portable Navigation Device (PND). It should beremembered, however, that the teachings of the present invention are notlimited to PNDs but are instead universally applicable to any type ofprocessing device that is configured to execute navigation software in aportable manner so as to provide route planning and navigationfunctionality. It follows therefore that in the context of the presentapplication, a navigation device is intended to include (withoutlimitation) any type of route planning and navigation device,irrespective of whether that device is embodied as a PND, a vehicle suchas an automobile, or indeed a portable computing resource, for example aportable personal computer (PC), a mobile telephone or a PersonalDigital Assistant (PDA) executing route planning and navigationsoftware.

Further, embodiments of the present invention are described withreference to a road network. It should be realised that the inventionmay also be applicable to other navigable networks, such as pedestrianpaths, rivers, canals, cycle paths or the like.

With the above provisos in mind, the Global Positioning System (GPS) ofFIG. 1 and the like are used for a variety of purposes. In general, theGPS is a satellite-radio based navigation system capable of determiningcontinuous position, velocity, time, and in some instances directioninformation for an unlimited number of users. Formerly known as NAVSTAR,the GPS incorporates a plurality of satellites which orbit the earth inextremely precise orbits. Based on these precise orbits, GPS satellitescan relay their location, as GPS data, to any number of receiving units.However, it will be understood that Global Positioning systems could beused, such as GLOSNASS, the European Galileo positioning system, COMPASSpositioning system or IRNSS (Indian Regional Navigational SatelliteSystem).

The GPS system is implemented when a device, specially equipped toreceive GPS data, begins scanning radio frequencies for GPS satellitesignals. Upon receiving a radio signal from a GPS satellite, the devicedetermines the precise location of that satellite via one of a pluralityof different conventional methods. The device will continue scanning, inmost instances, for signals until it has acquired at least threedifferent satellite signals (noting that position is not normally, butcan be determined, with only two signals using other triangulationtechniques). Implementing geometric triangulation, the receiver utilizesthe three known positions to determine its own two-dimensional positionrelative to the satellites. This can be done in a known manner.Additionally, acquiring a fourth satellite signal allows the receivingdevice to calculate its three dimensional position by the samegeometrical calculation in a known manner. The position and velocitydata can be updated in real time on a continuous basis by an unlimitednumber of users.

As shown in FIG. 1, the GPS system 100 comprises a plurality ofsatellites 102 orbiting about the earth 104. A GPS receiver 106 receivesGPS data as spread spectrum GPS satellite data signals 108 from a numberof the plurality of satellites 102. The spread spectrum data signals 108are continuously transmitted from each satellite 102, the spreadspectrum data signals 108 transmitted each comprise a data streamincluding information identifying a particular satellite 102 from whichthe data stream originates. The GPS receiver 106 generally requiresspread spectrum data signals 108 from at least three satellites 102 inorder to be able to calculate a two-dimensional position. Receipt of afourth spread spectrum data signal enables the GPS receiver 106 tocalculate, using a known technique, a three-dimensional position.

An exemplary navigation device 200, e.g. PND, is shown in FIG. 2; itshould be noted that the block diagram of the navigation device 200 isnot inclusive of all components of the navigation device, but is onlyrepresentative of many example components. The navigation device 200 islocated within a housing (not shown). The navigation device 200 includesprocessing circuitry comprising, for example, the processor 202mentioned above, the processor 202 being coupled to an input device 204and a display device, for example a display screen 206. Althoughreference is made here to the input device 204 in the singular, theskilled person should appreciate that the input device 204 representsany number of input devices, including a keyboard device, voice inputdevice, touch panel and/or any other known input device utilised toinput information. Likewise, the display screen 206 can include any typeof display screen such as a Liquid Crystal Display (LCD), for example.

In one arrangement, the input device 204 and the display screen 206 areintegrated so as to provide an integrated input and display device,including a touchpad or touchscreen input 250 (FIG. 3) to enable bothinput of information (via direct input, menu selection, etc.) anddisplay of information through the touch panel screen so that a userneed only touch a portion of the display screen 206 to select one of aplurality of display choices or to activate one of a plurality ofvirtual or “soft” buttons. In this respect, the processor 202 supports aGraphical User Interface (GUI) that operates in conjunction with thetouchscreen.

In the navigation device 200, the processor 202 is operatively connectedto and capable of receiving input information from input device 204 viaa connection 210, and operatively connected to at least one of thedisplay screen 206 and the output device 208, via respective outputconnections 212, to output information thereto. The navigation device200 may include an output device 208, for example an audible outputdevice (e.g. a loudspeaker). As the output device 208 can produceaudible information for a user of the navigation device 200, it shouldequally be understood that input device 204 can include a microphone andsoftware for receiving input voice commands as well. Further, thenavigation device 200 can also include any additional input device 204and/or any additional output device, such as audio input/output devicesfor example.

The processor 202 is operatively connected to memory 214 via connection216 and is further adapted to receive/send information from/toinput/output (I/O) ports 218 via connection 220, wherein the I/O port218 is connectible to an I/O device 222 external to the navigationdevice 200. The external I/O device 222 may include, but is not limitedto an external listening device, such as an earpiece for example. Theconnection to I/O device 222 can further be a wired or wirelessconnection to any other external device such as a car stereo unit forhands-free operation and/or for voice activated operation for example,for connection to an earpiece or headphones, and/or for connection to amobile telephone for example, wherein the mobile telephone connectioncan be used to establish a data connection between the navigation device200 and the Internet or any other network for example, and/or toestablish a connection to a server via the Internet or some othernetwork for example.

The memory 214 of the navigation device 200 comprises a portion ofnon-volatile memory (for example to store program code) and a portion ofvolatile memory (for example to store data as the program code isexecuted). The navigation device also comprises a port 228, whichcommunicates with the processor 202 via connection 230, to allow aremovable memory card (commonly referred to as a card) to be added tothe device 200.

FIG. 2 further illustrates an operative connection between the processor202 and an antenna/receiver 224 via connection 226, wherein theantenna/receiver 224 can be a GPS antenna/receiver for example and assuch would function as the GPS receiver 106 of FIG. 1. It should beunderstood that the antenna and receiver designated by reference numeral224 are combined schematically for illustration, but that the antennaand receiver may be separately located components, and that the antennamay be a GPS patch antenna or helical antenna for example.

It will, of course, be understood by one of ordinary skill in the artthat the electronic components shown in FIG. 2 are powered by one ormore power sources (not shown) in a conventional manner. Such powersources may include an internal battery and/or a input for a low voltageDC supply or any other suitable arrangement. As will be understood byone of ordinary skill in the art, different configurations of thecomponents shown in FIG. 2 are contemplated. For example, the componentsshown in FIG. 2 may be in communication with one another via wiredand/or wireless connections and the like. Thus, the navigation device200 described herein can be a portable or handheld navigation device200.

In addition, the portable or handheld navigation device 200 of FIG. 2can be connected or “docked” in a known manner to a vehicle such as abicycle, a motorbike, a car or a boat for example. Such a navigationdevice 200 is then removable from the docked location for portable orhandheld navigation use. Indeed, in other embodiments, the device 200may be arranged to be handheld to allow for navigation of a user.

Referring to FIG. 3, the navigation device 200 may be a unit thatincludes the integrated input and display device 206 and the othercomponents of FIG. 2 (including, but not limited to, the internal GPSreceiver 224, the processor 202, a power supply (not shown), memorysystems 214, etc.). The navigation device 200 may sit on an arm 252,which itself may be secured to a vehicle dashboard/window/etc. using asuction cup 254. This arm 252 is one example of a docking station towhich the navigation device 200 can be docked. The navigation device 200can be docked or otherwise connected to the arm 252 of the dockingstation by snap connecting the navigation device 200 to the arm 252 forexample. The navigation device 200 may then be rotatable on the arm 252.To release the connection between the navigation device 200 and thedocking station, a button (not shown) on the navigation device 200 maybe pressed, for example. Other equally suitable arrangements forcoupling and decoupling the navigation device 200 to a docking stationare well known to persons of ordinary skill in the art.

Various embodiments of the new guidance view of the present inventionwill now be described with reference to FIGS. 7 to 15.

FIG. 7 shows an example of the various components that may be used tocreate the 3D guidance view, e.g. roads 700 and 702, buildings andlandmarks 704, and trees and other greenery 706. The location, geometry,elevation and other information such as number of lanes, etc for roads700 and 702 are taken from map data, which is preferably stored on thedevice. Similarly, the appearance and location of buildings andlandmarks 704 is also taken from map data, again that is preferablystored on the device. The appearance of trees and other greenery 706 isgenerated from models again preferably stored on the device. Suchobjects are placed in suitable areas as indicated by the map data, e.g.rural or non-urban areas. The location of such objects is preferablyrandom rather than reflecting the actual location of such objects inreality.

In an embodiment of the invention, the user is shown a preview of anapproaching junction by the position of the camera advancing along thepredetermined route. As will be appreciated, the advancement of thecamera is performed such that the current position of the device can nolonger be seen in the navigation view. In other words, the camerafast-forwards along the path being traveled to preview an upcomingdecision point, e.g. junction, intersection, etc. In embodiments theelevation and/or pitch angle of the camera is also changed, with inpreferred embodiments, the camera moving to a smaller elevation and agreater pitch angle than is used for normal guidance.

An example of this functionality is illustrated in FIGS. 8A to 8J. Inthese figures, a vehicle (with a navigation device) is travelling froman origin 800 to a destination 802 along the schematic path 803. Thecurrent position of the vehicle along the path 803 is shown by themarker 804, and by the icon 806 in the guidance view 805.

In FIG. 8A, the vehicle is shown travelling in the outer lane of theroad along the predetermined path 807. FIG. 8A shows the camera in itsusual guidance position, with the camera being located at a firstelevation and pitch angle. The pitch angle in this example being 30°,although it will be appreciated that any angle, such as between 20° to40°, may be used as desired.

FIG. 8B shows the vehicle having advanced along the path 807 to a pointa predetermined distance in front of “junction 1”. The predetermineddistance may be based on the type of road currently being traveled, e.g.highway, major road, minor road etc, environmental factors, a profile ofthe driver or the like. When the device (and thus vehicle) reaches thispoint, the camera will stop its concurrent movement with that of thevehicle (i.e. tracking the current position of the device), and begin toadvance along the predetermined path towards the junction, at least bymoving in the x-y plane. The camera may also decrease in elevationand/or increase in pitch angle as it advances towards the junction. Thismovement can best be seen by the change in view between FIG. 8B (startof the transition) and FIG. 8C (middle of the transition) and FIG. 8D(end of the transition).

An audible message warning the user may the approaching junction mayalso be issued, e.g. at the same time as the advancement of the camera.For example, in the embodiment shown, the audible message is deliveredto the user when the device reaches the point denoted “start voicemessage” on path 803.

In FIG. 8D, the camera has reached a predetermined position associatedwith the junction, such that the user is able to see details about theupcoming junction. This predetermined position is denoted as point “zoom1” on the schematic path 803. As will be seen, the user is now able toclearly see the geometry of the junction, the manoeuvre to be made atthe junction and the desired choice of lane. As seen in FIG. 8D, thecamera has a larger pitch angle when in this position; preferablybetween 50° and 70°, and most preferably 60°.

The camera stays in this position until the current position of thedevice (which has continued to move towards the junction during thistime) reaches the start of the junction. This is shown in FIG. 8Ewherein the icon 806 representative of the current position of thedevice has just come back into view on the screen. Once the devicereaches the junction, the camera begins to transition back to its normalposition tracking the movements of the device, e.g. by raising inelevation and reducing the pitch angle. This movement can best be seenby the change in view between FIG. 8F and FIG. 8G. in preferredembodiments this transition involves an increase in elevation of thecamera position (to the original elevation) and a reduction of pitchangle (to the original pitch angle).

FIGS. 8G to 8J show a similar set of camera transitions in respect of“junction 2” with the camera fast forwarding to preview the junctionbetween the points denoted “start voice message” and “zoom 2” on theschematic path 803, and reverting back to the normal guidance positionafter the vehicle has passed the beginning of the junction denoted by“junction 2” on the schematic path 803.

FIG. 9 depicts how (i) the speed of the camera along the calculatedroute, (ii) the camera elevation, and (iii) the pitch angle of thecamera changes will time as the device (and associated vehicle) travelsalong the path 803.

For example, it can be seen that the pitch angle increases, e.g. fromaround 30° to 60°, as the junction is approached. The camera stays atthis pitch angle until the device reaches the junction, at which timethe pitch angle quickly decreases back to its original value, e.g. of30°. Preferably the increase in pitch angle occurs over a longer timeperiod than the reversion of the pitch angle back to its original value;this emphasises the fast-forward movement of the camera. While thechange in pitch angle is shown as occurring linearly with time, it willbe appreciated that the change may occur in a non-linear manner.

Similarly, it can be seen that the elevation of the camera decreases asthe junction is approached. The camera stays at this elevation until thedevice reaches the junction, at which time the camera increases inelevation to return to its original height. Preferably the decrease inelevation occurs over a longer time period than the increase inelevation back to its original value; this emphasises the fast-forwardmovement of the camera. While the decrease in elevation is shown asoccurring non-linearly, and the subsequent increase in elevation isshown as occurring linearly, it will be appreciated that eithertransition may occur in any desired manner, e.g. linearly ornon-linearly.

It can be also been seen in FIG. 9 that the speed of the camera alongthe path 803 increases rapidly to “fast-forward” the camera ahead of thedevice, and thus preview an approaching junction, before dropping to aspeed slower than the current vehicle speed (to allow the device tocatch-up). As will be appreciated, the speed of the camera when in its“zoomed” position may be zero or a non-zero value (e.g. as shown in FIG.9) as desired provided it is less than the current speed of the device.This speed may be a predetermined speed, or it may be based on thecurrent speed of the device. The changes in speed of the camera may bechosen as desired to provide a desired user experience; thus it will beappreciated that the changes shown in FIG. 9 are merely exemplary.

Typically, the camera will stay in the zoomed position until the devicereaches the junction. It will be appreciated, however, that, for exampledue to traffic congestion, the device may be delayed in reaching thejunction. The camera may therefore perform a reverse manoeuvre or othertype of transition back to the current position of the device (and theoriginal camera settings used to track the movements of the device) ifthe vehicle speed drops below a certain speed or the camera is in azoomed position for more than a predetermined period of time. In otherwords, in some embodiments, the camera may automatically move back toshow the current position of the device

FIGS. 10A and 10B illustrate a further embodiment in which the cameramoves back to show the current position of the device based on userinput. In FIG. 10A, a selectable option is provided to the user, e.g.the selectable icon 900, which when selected moves the camera back tosee his own position again, e.g. as shown in FIG. 10B (the currentposition of the device being shown by the icon 904). A furtherselectable option may also be provided to the user, e.g. the selectableicon 902 of FIG. 10B, which will cause the camera to again fast-forwardto the junction. Therefore, in embodiments, the camera can be made tofast-forward to preview an approaching decision point based on userinput.

Other aspects of the present invention will now be described, which canbe used separately from, or in combination with, the above describedfast-forwarding camera functionality. Each of the following aspects canalso be used separately, or in any combination as desired.

FIG. 11 illustrates an embodiment of the guidance view in whichdistinctions are made between more and less relevant roads. A focus ispreferably put on the road currently being traveled, therefore limitingthe distraction of the user by other roads also on the screen. Forexample, road markings are not shown on roads that the user is not ableto enter, e.g. road 911, from their current road 910. For roads that theuser can enter from their current position, e.g. road 916, road markingsare shown for a predetermined distance from the junction and are thenfaded out. Road markings can include lane dividers 913, pedestriancrossings 914, arrows 912, stop lines 917, etc.

In embodiments, some road markings, such as the arrows 912 shown in FIG.11, are not shown in a position illustrative of their real-worldlocation. For example, the arrows 912 are always shown just before thejunction such that they are always shown in the junction preview. Thearrows are also only shown once on the road unlike reality in whichtypically they are shown multiple times on a road.

FIG. 12 illustrates an embodiment of the guidance view of the inventionin which the transparency of the displayed calculated route beingfollowed by the user is varied. For example, as shown in FIG. 12, theportion of the route 920 around the current position of the device (i.e.at the bottom of the screen) is shown in a semi-transparent manner, e.g.such that the road markings are visible. This portion of the route maybe a predetermined distance in front of and behind the current position.Conversely, the portion of the route that is more than a predetermineddistance in front of the current position, or a predetermined distanceafter the approaching junction, is shown in an opaque manner.

In embodiments, as shown in FIG. 13, the displayed route may encompassany lane that the user is able to travel in along the calculated route,rather than just the current lane in which they are travelling.

In embodiments, as shown in FIGS. 14A and 14B, the guidance view may besupplemented with additional information, e.g. an icon 930 indicatingthe phase of an approaching traffic control signal, an road sign 932,etc.

In embodiments, the guidance view can be used to advise a user to switchlanes. As will be appreciated, it is in important in at least theseembodiments to ascertain in which lane a user a currently travelling.This may be determined only using information obtained from the globalnavigation satellite system (GNSS) receiver, but may be supplemented byusing information from a camera, laser or other imaging sensorassociated with the device to more accurately determine the location ofthe device. For example, substantial research has been carried out inrecent years, in which image data from one or more video cameras mountedwithin a vehicle is analysed, e.g. using various image processingtechniques, to detect and track the lane in which the vehicle istravelling. In preferred embodiments, the positioning informationobtained from the GNSS receiver, and optionally one or more imagesensors, is used together with map data indicating the number of lanes,geographic position and geometry to display lane guidance information toa user. For example, the current lane in which a vehicle is travellingin a multi-lane carriageway can be determined, for example, using themethod set out in the paper “Multi-lane detection in urban drivingenvironments using conditional random fields” authored by Junhwa Hur,Seung-Nam Kang, and Seung-Woo Seo. published in the proceedings of theIntelligent Vehicles Symposium, page 1297-1302. IEEE, (2013). Here, theportable navigation device may be provided with a data feed from a videocamera, radar and/or lidar sensor and an appropriate algorithm is usedto process the received data in real-time to determine a current lane ofthe device or the vehicle in which the device is travelling.Alternatively, another device or apparatus, separate from the portablenavigation device, such as a Mobileye system available from MobileyeN.V. may provide the determination of the current lane of the vehicle onthe basis of these data feeds and then feed the determination of thecurrent lane to the portable navigation device, for example by a wiredconnection or a Bluetooth connection.

For example, as shown in FIG. 15A, a user is advised to switch fromcurrent lane 940 to another lane 941 by a transition, e.g. curved,portion 942 in the displayed route. If the user does not follow thisinstruction to switch lanes, the transition, e.g. curved, portion movesforward along the current road toward the current position of the user(e.g. as shown by icon 944). This is shown, for example, by FIG. 15B.

Another example for providing lane guidance to a user will now bedescribed with reference to FIGS. 16A to 16F.

In FIG. 16A, a user, indicated by the icon 1006, is shown following apredetermined route 1005, which includes an instruction 1000 to changelanes after junction 1009 from lane 1004 to lane 1002. Preferably, theinstruction to change lanes is associated with a manoeuvre to be made atan approaching junction, indicated by the icon 1007. The instruction1000 can be shown at a predetermined distance or time from the junction,or, for example, may be positioned at the first opportunity to changelanes for the approaching junction; in this case after junction 1009.

In FIG. 16B, the user is shown having progressed along the route 1005,and is soon to reach the position along the route at which the lanechange instruction 1000 is associated. The user may change lanes as soonas instructed; however in many cases the user will choose not to, or beunable to (e.g. due to traffic on the road), switch lanes wheninstructed. In such cases, the instruction 1000 is arranged to moveconcurrently along the route with the user, e.g. as shown in FIG. 16C.The concurrent movement of the current position icon 1006 and the lanechange instruction 1000 begins when the user is a predetermined distancebefore the instruction 1000; the concurrent movement thereby maintainingthe predetermined distance between the position icon 1006 and theinstruction 1000. The combined movement of the current position icon1006 and lane change instruction 1000 on the display preferablycontinues until the user makes the switch in lane (or, for example,until the camera moves to preview the approaching junction).

In FIG. 16D, the camera has begun its fast-forward movement to previewthe manoeuvre 1007 to be made at the approaching junction. The currentposition of the user is shown by icon 1008, which remains in lane 1004thereby indicating that the user has still to change lanes.

FIG. 16E shows a later time, although still prior to the user havingarrived at the approaching junction, where the icon 1008 indicating thecurrent position of the user is now shown in lane 1002. The user hastherefore now changed lanes according to the instruction 1000, asrequired for the manoeuvre 1007 at the junction.

Finally, FIG. 16F shows the user in the process of making the manoeuvre1007 at the junction.

Any of the methods in accordance with the present invention may beimplemented at least partially using software e.g. computer programs.The present invention thus also extends to a computer program comprisingcomputer readable instructions executable to perform, or to cause anavigation device to perform, a method according to any of the aspectsor embodiments of the invention. Thus, the invention encompasses acomputer program product that, when executed by one or more processors,cause the one or more processors to generate suitable images (or othergraphical information) for display on a display screen. The inventioncorrespondingly extends to a computer software carrier comprising suchsoftware which, when used to operate a system or apparatus comprisingdata processing means causes, in conjunction with said data processingmeans, said apparatus or system to carry out the steps of the methods ofthe present invention. Such a computer software carrier could be anon-transitory physical storage medium such as a ROM chip, CD ROM ordisk, or could be a signal such as an electronic signal over wires, anoptical signal or a radio signal such as to a satellite or the like. Thepresent invention provides a machine readable medium containinginstructions which when read by a machine cause the machine to operateaccording to the method of any of the aspects or embodiments of theinvention.

Where not explicitly stated, it will be appreciated that the inventionin any of its aspects may include any or all of the features describedin respect of other aspects or embodiments of the invention to theextent they are not mutually exclusive. In particular, while variousembodiments of operations have been described which may be performed inthe method and by the apparatus, it will be appreciated that any one ormore or all of these operations may be performed in the method and bythe apparatus, in any combination, as desired, and as appropriate.

The invention claimed is:
 1. A device for generating navigationinstructions for display on a display device of a portable navigationdevice, the device comprising one or more processors arranged to: accessa repository storing digital map data pertaining to a navigable networkalong which the device can travel, the digital map data including datapertaining to available lanes of the navigable network; generate, fordisplay on the display device, a three-dimensional perspective view of amodel representative of the map data as though from a camera positionedat an elevation and pitch angle behind a current position of the device,that is updated to follow the device as it travels along a plannedroute, wherein the three-dimensional perspective view shows theavailable lanes of the navigable network, and wherein the planned routeto be followed is shown in the view as a line, the line showing theroute to be followed as passing along a determined current lane in whichthe device is travelling; adapt the generated view, in response todetecting that the determined current lane in which the device istravelling differs from a lane or lanes associated with a maneuver to bemade at an upcoming decision point in order to follow the planned route,such that the line showing the route to be followed is shaped toindicate an instruction to the user to change lanes, wherein theinstruction is initially positioned at a predetermined distance or timefrom the upcoming decision point or at a first opportunity to changelanes for the upcoming decision point; and adapt the generated view suchthat the line showing the route to be followed continues to indicate theinstruction to the user to change lanes as the movement of the device isfollowed by the instruction moving concurrently with the position of thedevice, until a determination is made that the current lane of thedevice is changed in accordance with the instruction, wherein theconcurrent movement of the instruction with the position of the devicestarts when the current position of the device is at a predetermineddistance before the instruction, thereby maintaining the predetermineddistance between the position of the device and the instruction.
 2. Thedevice as claimed in claim 1, wherein the instruction to change lanes isassociated with the manoeuvre to be made at the upcoming decision pointin order to follow the planned route.
 3. The device as claimed in claim1, wherein the one or more processors are further arranged to adapt thegenerated view, in response to the determination that the current laneof the device is changed in accordance with the instruction, such thatthe line showing the route to be followed no longer shows theinstruction to the user to change lanes.
 4. The device as claimed inclaim 1, wherein, in use, the three-dimensional perspective view showsthe available lanes of the navigable network by way of road markings. 5.The device as claimed in claim 4, wherein the road markings are onlyshown in the rendered view on parts of the navigable network relevant tothe planned route.
 6. The device as claimed in claim 4, wherein the roadmarkings are only shown in the rendered view on parts of the navigablenetwork local to a detected position of the device.
 7. The device asclaimed in claim 4, wherein the road markings are generated based on thedigital map data.
 8. The device as claimed in claim 1, wherein the oneor more processors are further arranged to determine a current lane ofthe navigable network in which the device is travelling based on datareceived from one or more of a camera, lidar sensor, radar, globalnavigation satellite system (GNSS) receiver, and an inertial measurementunit.
 9. The device as claimed in claim 1, wherein the three-dimensionalperspective view as though from the camera positioned at the elevationand pitch angle behind the current position of the device includes anicon representative of the device in a current position of the device inthe lanes of the navigable network.
 10. The device as claimed in claim1, wherein the line showing the route to be followed covers each of twoor more lanes that can be occupied to successfully complete themanoeuvre to be made at an approaching junction in order to follow theplanned route.
 11. A method of generating navigation instructions fordisplay on a display device of a portable navigation device, the methodcomprising: accessing a repository storing digital map data pertainingto a navigable network along which the device can travel, the digitalmap data including data pertaining to available lanes of the navigablenetwork; generating, for display on the display device, athree-dimensional perspective view of a model representative of the mapdata as though from a camera positioned at an elevation and pitch anglebehind a current position of the device, that is updated to follow thedevice as it travels along a planned route, wherein thethree-dimensional perspective view shows the available lanes of thenavigable network, and wherein the planned route to be followed is shownin the view as a line, the line showing the route to be followed aspassing along a determined current lane in which the device istravelling; adapting the generated view, in response to detecting thatthe determined current lane in which the device is travelling differsfrom a lane or lanes associated with a maneuver to be made at anupcoming decision point in order to follow the planned route, such thatthe line showing the route to be followed is shaped to indicate aninstruction to the user to change lanes, wherein the instruction isinitially positioned at a predetermined distance or time from theupcoming decision point or at a first opportunity to change lanes forthe upcoming decision point; and adapting the generated view such thatthe line showing the route to be followed continues to indicate theinstruction to the user to change lanes as the movement of the device isfollowed by the instruction moving concurrently with the position of thedevice, until a determination is made that the current lane of thedevice is changed in accordance with the instruction, wherein theconcurrent movement of the instruction with the position of the devicestarts when the current position of the device is at a predetermineddistance before the instruction, thereby maintaining the predetermineddistance between the position of the device and the instruction.
 12. Anon-transitory computer readable medium comprising instructions which,when executed by one or more processors of a device, cause the device toperform a method for generating navigation instructions for display on adisplay device of a portable navigation device, the method comprising:accessing a repository storing digital map data pertaining to anavigable network along which the device can travel, the digital mapdata including data pertaining to available lanes of the navigablenetwork; generating, for display on the display device, athree-dimensional perspective view of a model representative of the mapdata as though from a camera positioned at an elevation and pitch anglebehind a current position of the device, that is updated to follow thedevice as it travels along a planned route, wherein thethree-dimensional perspective view shows the available lanes of thenavigable network, and wherein the planned route to be followed is shownin the view as a line, the line showing the route to be followed aspassing along a determined current lane in which the device istravelling; adapting the generated view, in response to detecting thatthe determined current lane in which the device is travelling differsfrom a lane or lanes associated with a maneuver to be made at anupcoming decision point in order to follow the planned route, such thatthe line showing the route to be followed is shaped to indicate aninstruction to the user to change lanes, wherein the instruction isinitially positioned at a predetermined distance or time from theupcoming decision point or at a first opportunity to change lanes forthe upcoming decision point; and adapting the generated view such thatthe line showing the route to be followed continues to indicate theinstruction to the user to change lanes as the movement of the device isfollowed by the instruction moving concurrently with the position of thedevice, until a determination is made that the current lane of thedevice is changed in accordance with the instruction, wherein theconcurrent movement of the instruction with the position of the devicestarts when the current position of the device is at a predetermineddistance before the instruction, thereby maintaining the predetermineddistance between the position of the device and the instruction.